docs: add bilingual README

- add an English README and a Chinese translation with cross links,
  following the standard README.zh-CN.md convention
- cover packages, install prerequisites (authorizer chain), development
  workflow, and license

README.md

@@ -0,0 +1,46 @@
+# pi-extensions
+
+English | [简体中文](README.zh-CN.md)
+
+Personal extensions for the [pi](https://www.npmjs.com/package/@earendil-works/pi-coding-agent) coding agent, focused on Bash permissions: unwrap, inspect, and re-adjudicate commands before they run.
+
+## Packages
+
+| Package | Description |
+|---|---|
+| [pi-permission-ai-judge](packages/pi-permission-ai-judge) | AI judge — a model rules allow / deny / defer on each pending Bash ask; shadow logs only, enforce auto-approves |
+| [pi-permission-inner-cmd](packages/pi-permission-inner-cmd) | Unwraps transparent Bash wrappers (`timeout`, `time`, …) and authorizes the inner command |
+
+## Install
+
+```bash
+pi install git:github.com/SikongJueluo/pi-extensions
+```
+
+The package manifest (root `package.json`, `pi.extensions`) mounts both extensions declaratively — effective in any directory. Prerequisites:
+
+1. Enable [`@gotgenes/pi-permission-system`](https://github.com/gotgenes/pi-permission-system) ≥ 32
+2. Add the extensions to the authorizer chain — order is consultation order, UI sessions only:
+
+```jsonc
+// ~/.pi/agent/extensions/pi-permission-system/config.json
+{ "authorizerChain": ["inner-cmd", "ai-bash-judge"] }
+```
+
+See the ai-judge [README](packages/pi-permission-ai-judge/README.md) for modes, judge model, and guardrails.
+
+## Development
+
+pnpm workspace, TypeScript + vitest.
+
+```bash
+pnpm install
+pnpm check   # tsc --noEmit
+pnpm test    # vitest run
+```
+
+Design decisions live in [docs/adr/](docs/adr/).
+
+## License
+
+GPL-3.0